X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=7a26e9ed7ba21c6645860ac747138e999d39d2e9;hb=8aeee8db21858becb45a8e9f6b5bc23109638bcb;hp=33937e7627e460328979a1ff809af94e2e0f3b98;hpb=2fdea17c3da17f6ae96601283b28d025ed4d4cee;p=musl

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 33937e76..7a26e9ed 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -92,10 +92,12 @@ static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char
 }
 
 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON)
+#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK)
 
 static void *find_sym(struct dso *dso, const char *s, int need_def)
 {
 	uint32_t h = hash(s);
+	void *def = 0;
 	if (h==0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1;
 	if (h==0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1;
 	for (; dso; dso=dso->next) {
@@ -103,10 +105,14 @@ static void *find_sym(struct dso *dso, const char *s, int need_def)
 		if (!dso->global) continue;
 		sym = lookup(s, h, dso->syms, dso->hashtab, dso->strings);
 		if (sym && (!need_def || sym->st_shndx) && sym->st_value
-		 && (1<<(sym->st_info&0xf) & OK_TYPES))
-			return dso->base + sym->st_value;
+		 && (1<<(sym->st_info&0xf) & OK_TYPES)
+		 && (1<<(sym->st_info>>4) & OK_BINDS)) {
+			if (def && sym->st_info>>4 == STB_WEAK) continue;
+			def = dso->base + sym->st_value;
+			if (sym->st_info>>4 == STB_GLOBAL) break;
+		}
 	}
-	return 0;
+	return def;
 }
 
 static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t stride, Sym *syms, char *strings, struct dso *dso)
@@ -298,7 +304,7 @@ static struct dso *load_library(const char *name)
 				if (!libc->prev) {
 					tail->next = libc;
 					libc->prev = tail;
-					tail = libc;
+					tail = libc->next ? libc->next : libc;
 				}
 				return libc;
 			}
@@ -440,10 +446,15 @@ void *__dynlink(int argc, char **argv, size_t *got)
 	size_t *auxv, aux[AUX_CNT] = {0};
 	size_t app_dyn[DYN_CNT] = {0};
 	size_t lib_dyn[DYN_CNT] = {0};
+	size_t vdso_dyn[DYN_CNT] = {0};
 	size_t i;
 	Phdr *phdr;
 	Ehdr *ehdr;
-	struct dso lib, app;
+	static struct dso builtin_dsos[3];
+	struct dso *const app = builtin_dsos+0;
+	struct dso *const lib = builtin_dsos+1;
+	struct dso *const vdso = builtin_dsos+2;
+	size_t vdso_base=0;
 
 	/* Find aux vector just past environ[] */
 	for (i=argc+1; argv[i]; i++)
@@ -453,6 +464,13 @@ void *__dynlink(int argc, char **argv, size_t *got)
 
 	decode_vec(auxv, aux, AUX_CNT);
 
+	for (i=0; auxv[i]; i+=2) {
+		if (auxv[i]==AT_SYSINFO_EHDR) {
+			vdso_base = auxv[i+1];
+			break;
+		}
+	}
+
 	/* Only trust user/env if kernel says we're not suid/sgid */
 	if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
 	  || aux[AT_GID]!=aux[AT_EGID]) {
@@ -471,7 +489,7 @@ void *__dynlink(int argc, char **argv, size_t *got)
 		}
 	}
 
-	app = (struct dso){
+	*app = (struct dso){
 		.base = 0,
 		.strings = (void *)(app_dyn[DT_STRTAB]),
 		.hashtab = (void *)(app_dyn[DT_HASH]),
@@ -479,10 +497,10 @@ void *__dynlink(int argc, char **argv, size_t *got)
 		.dynv = (void *)(phdr->p_vaddr),
 		.name = argv[0],
 		.global = 1,
-		.next = &lib
+		.next = lib
 	};
 
-	lib = (struct dso){
+	*lib = (struct dso){
 		.base = (void *)aux[AT_BASE],
 		.strings = (void *)(aux[AT_BASE]+lib_dyn[DT_STRTAB]),
 		.hashtab = (void *)(aux[AT_BASE]+lib_dyn[DT_HASH]),
@@ -493,41 +511,53 @@ void *__dynlink(int argc, char **argv, size_t *got)
 		.relocated = 1
 	};
 
+	if (vdso_base) {
+		ehdr = (void *)vdso_base;
+		phdr = (void *)(vdso_base + ehdr->e_phoff);
+		for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
+			if (phdr->p_type == PT_DYNAMIC)
+				vdso->dynv = (void *)(vdso_base + phdr->p_offset);
+			if (phdr->p_type == PT_LOAD)
+				vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
+		}
+		decode_vec(vdso->dynv, vdso_dyn, DYN_CNT);
+		vdso->syms = (void *)(vdso->base + vdso_dyn[DT_SYMTAB]);
+		vdso->hashtab = (void *)(vdso->base + vdso_dyn[DT_HASH]);
+		vdso->strings = (void *)(vdso->base + vdso_dyn[DT_STRTAB]);
+		vdso->name = "linux-gate.so.1";
+		vdso->global = 1;
+
+		vdso->prev = lib;
+		lib->next = vdso;
+	}
+
 	/* Relocate the dynamic linker/libc */
 	do_relocs((void *)aux[AT_BASE], (void *)(aux[AT_BASE]+lib_dyn[DT_REL]),
-		lib_dyn[DT_RELSZ], 2, lib.syms, lib.strings, &app);
+		lib_dyn[DT_RELSZ], 2, lib->syms, lib->strings, app);
 	do_relocs((void *)aux[AT_BASE], (void *)(aux[AT_BASE]+lib_dyn[DT_RELA]),
-		lib_dyn[DT_RELASZ], 3, lib.syms, lib.strings, &app);
+		lib_dyn[DT_RELASZ], 3, lib->syms, lib->strings, app);
 
 	/* At this point the standard library is fully functional */
 
-	reclaim_gaps(app.base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
-	ehdr = (void *)lib.base;
-	reclaim_gaps(lib.base, (void *)(lib.base+ehdr->e_phoff),
+	reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
+	ehdr = (void *)lib->base;
+	reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
 		ehdr->e_phentsize, ehdr->e_phnum);
 
-	head = tail = &app;
-	libc = &lib;
-	app.next = 0;
+	head = tail = app;
+	libc = lib;
+	app->next = 0;
 	load_deps(head);
 
 	make_global(head);
 	reloc_all(head->next);
 	reloc_all(head);
 
-	if (rtld_used) {
-		runtime = 1;
-		head->next->prev = malloc(sizeof *head);
-		*head->next->prev = *head;
-		head = head->next->prev;
-		libc->prev->next = malloc(sizeof *libc);
-		*libc->prev->next = *libc;
-		libc = libc->prev->next;
-		if (libc->next) libc->next->prev = libc;
-		if (tail == &lib) tail = libc;
-	} else {
+	runtime = 1;
+	if (!rtld_used) {
 		free_all(head);
 		free(sys_path);
+		reclaim((void *)builtin_dsos, 0, sizeof builtin_dsos);
 	}
 
 	errno = 0;